1. Field of the Invention
The present invention relates to a display device having a plurality of light emitting elements disposed in a matrix form on a display panel, the luminance of each light emitting element being controlled by a current value, and more particularly to a display device and an electronic apparatus capable of controlling the temperature of a display panel with a simple configuration.
2. Description of Related Art
In a display device having a large number of light emitting elements disposed in a matrix form on a display panel, the luminance of each light emitting element being controlled by a current value, it is generally required to increase a value of current to be supplied to each light emitting element in order to obtain a high luminance. However, as the current value is increased, the light emitting element generates heat, shortening a lifetime of the element.
An emission efficiency of a light emitting element has improved in recent years, and a signal level in an ordinary image display state is reduced by more than half of a signal level presenting a maximum luminance. The lifetime of a light emitting element is therefore rarely shortened by heat generation. However, for example, in the worst state that a full white display state continues for a long time, a light emitting element may generate heat and be damaged.
In order to settle this issue, there has been proposed a display device (e.g., refer to Japanese Unexamined Patent Application Publication No. 2005-31430 (hereinafter referred to as “patent document 1”)) in which an operational environment temperature of a display panel is detected, and when this temperature exceeds a predetermined temperature (e.g., 50° C.), a drive voltage value of a light emitting element is changed and each light emitting element is driven to make a luminance value of the light emitting element lower than a predetermined luminance value.
In another display device (e.g., refer to Japanese Unexamined Patent Application Publication No. 2002-175046 (hereinafter referred to as “patent document 2”)), a temperature detector is provided to each of a number of organic electro luminescence elements (hereinafter called “organic EL element”) serving as light emitting elements and disposed in a matrix form, and emission control of each organic EL element is performed using temperature data detected with each temperature detector.
Of known display devices, the display device described in the patent document 1 detects the operational environment temperature of the display panel. Therefore, a change in the operational environment temperature is small, for example, even if the light emitting elements generate heat because a full white display state continues, and it is difficult to immediately detect a temperature rise in the light emitting elements. It is therefore impossible to perform efficient temperature control of the display panel and suppress the light emitting elements from being damaged by heat generation.
The display device described in the patent document 2 provides the temperature detector to each of the number of organic EL elements. Therefore, although a temperature rise in the organic EL elements can be detected immediately and controlled properly, there is a fear that the structure becomes complicated and a cost of the display device rises.